I got a chance to listen to the Denon DCD 660. Just a preface though this was absolutely subjective listneing non level matched non double blind. And I understand that any differences heard would be hard to be taken seriously if at all on a forum like this. So fair warning. I'm not making any claims here. Ahem - your mileage may vary and your skepticism meter will be off the charts. So, rest assured, I have heard the standard protests before, and acknowledge them.
....But I thought you'd be interested in an update anyway.
The gentleman that picked it up said he got it for just five bucks. It's taken some wear and tear from age. The transport tray takes some coaxing to make it fully eject and close. It stops halfway. It skips a little bit especially at the beginning of discs.
I wasn't expecting much in terms of sound considering this was from the late 80's. Its SNR was 95db with a 100db channel separation.
I compared it to my Emotiva DC-1 via digital and used the preamp to switch back and forth.
Well it sounded different and more importantly it sounded great to me. It did some things my DC-1 could not do. Namely in timing. Yes that makes no sense. The timing of these clocks are already at very inaudible levels. But whatever it was things appeared very fast. As in they just appeared. While with the DC-1 there was a bit of vagueness to things. So for instance with a drum and a bass note played together. The drum whacks hard and the bass plays nice and full at the same time. With the DC-1 when they happen together, things sound a little more mushy. In classical music namely is where this thing separated itself. I could follow the melodies of almost all the instruments I heard very clearly. Which honestly I normally don't in classical music.
With the DC-1 I would have to think about what melody lines I'd have to follow. While with this one, all the different melody lines were simply there.
So in a way I didn't have to try to listen to the music and place objects.
Another thing it did was with the way it portrayed all kinds of dynamics. For instance I was listenign to a peice of cello/violin music. The cello was playing notes very fast, at about 1/2 or a 1/3 of a second. Well with other DACs, I'd here these fast notes. But with the Denon, I could hear the variations in dynamics within the bows more easily. I didn't have to focus at all. When the player changes directions on the bow the bow acclerates and slow down within the bowing motion to produce different dynamics and types of timbre very quickly. Well I was able to hear this. While with the DC-1 it was not as obvious. What was obvious was that he was playing a bunch of cello notes.
The DC-1 is the best DAC I've heard. So I was surprised. The DC-1 in comparison has a warmer sound and does produce a bit more depth and room ambience. The 3 dimensional body of instruments feels more rounded and fuller with the DC-1. While with the Denon the body is there but it feels like a different sort of shape. The Denon also produces more sensation of impact on drums.
The Denon's type of sound most reminded me of the Gungnir multibit which also had this canny ability with better timing.
On the cons side both the Denon and the Gungnir suffered from a harsh treble tone. This harshness reduces after leaving the unit on for a day. The Gungnir never really got rid of that tone even after a few weeks. The Denon still has it but it has reduced, but either way there is a peakiness still on the treble in a certain region. This could also explain the difference in sound and speed. But after some thought, I think there's still something else going on.
Either way, I'm having a great time listening to it.